/Engine/Source/Runtime/MovieScene/Public/Evaluation/PreAnimatedState/MovieScenePreAnimatedStateStorage.h
Replace the key associated with a particular storage index
void ReplaceKey ( [FPreAnimatedStorageIndex](API\Runtime\MovieScene\Evaluation\PreAnimatedState\FPreAnimatedStorageIndex) StorageIndex, const [KeyType](API\Runtime\MovieScene\Evaluation\PreAnimatedState\TPreAnimatedStateStorage\KeyType) & NewKey )